<?php
function test15(int $x) : ?int {
    return match($x) {
        1, 2 => throw new Exception(),
        3 => 'invalid',
    };
}
function test_suspicious_scalar(): string {
    return match(2) {
        1 => 'x',
        2 => 'y',
        3 => 'invalid',
    };
}
function test_suspicious_type(string $key): string {
    return match($key) {
        1 => 'x',
        null => 'y'
    };
}
